The present invention relates to a noise rejecting compensation circuit for developing apparatus. This apparatus is replenished with developing liquid during a time when the integral value derived from summing up an electric signal through integrator means by predetermined periods reaches a predetermined value from another value. The above-mentioned electric signal is transformed through photocell means from a light emitted from light source means and interfered with film means. In the subject circuit of the present invention, differential amplifier means is provided at the input side of the integrator means, leakage by-pass having condenser means is connected with the differential amplifier means in parallel, and leakage contact means closed at a time when the light source means is turned off is inserted in the leakage by-pass means.